Generally, a navigation device, such as a vehicle-mounted navigation device, provides route guidance for the driver by using a voice output, a graphic display, etc. when the vehicle approaches a predetermined point (e.g., an intersection or the like where the vehicle should change its traveling direction) while travelling along a set route. However, while the navigation device can provide route guidance at a preset certain point, the navigation device cannot present the driver with the content of route guidance which a fellow passenger provides for the driver while the vehicle is travelling as a route guidance content from the navigation device.
A problem is therefore that the driver cannot drive the vehicle according to a fellow passenger's route guidance if he or she mishears the fellow passenger's route guidance or misses the fellow passenger's route guidance due to a surrounding noise. To solve this problem, for example, patent reference 1 describes a voice recognition device that always recognizes a voice and displays the result of the recognition in characters on a screen, just as it is.